legia ccerulea Torr., Mertensia sibirica Don., and Pohmonium hu- 

 mile Willd. It would have been interesting Inter in the season to 

 have made a more thorough examination of the high alpine expos- 

 ures, which from their isolated position would doubtless afford 

 rare or new species. The exchange from the cool snow-drifts of 

 Pine mountain to the oven heat of St. George proved much less 

 pleasant than the reverse process, though more easily accom- 

 plished. It is worthy of remark in this connection to note the 

 mutual dependence of these two strongly contrasted but adjoining 

 districts. Thus the moisture, condensed either in the form of sum- 

 mer rain or winter snow on these high mountain ridges, is not all 

 exposed in open water courses to be directly returned to the at- 

 mosphere by the intense evaporation of the lower desert tracts. A 

 large part of it sinks into the pervious sandstone strata, dipping 

 towards the south, thence working its way through deep unseen 

 channels, it breaks out in the form of copious springs at the base 

 of the high cliffs bounding the Valley of the Virgen. From this 

 source is derived the necessary supplies of irrigating water for the 

 gardens of Washington and St. George. In return, these semi- 

 tropical districts contribute to the dwellers in the mountains the 

 elaborated products of the choicest garden fruits that would be 

 otherwise unattainable. Without such a mutual exchange neither 

 of these sections would be as well adapted as now for civilized 



On the 25th of June having completed my botanical collection 

 in the valley of the Virgen, I left on my return route to Salt Lake, 

 having arranged to spend a few weeks in the more elevated dis- 

 tricts within the rim of the great basin. 



On reaching Cedar city, sixty miles to the north of St. George, 

 in the latter part of June, it was hot very encouraging to note that 

 the continued dry season had in a great measure completed the de- 

 velopment of the early Spring plants, which were but scantily suc- 

 ceeded by later summer forms. On the rocky and variegated 

 marly exposures adjoining the town, the conditions seemed es- 

 pecially favorable for a peculiar flora, and this expectation was in 

 a measure realized, though in scanty forms. Among these is a 

 well marked new species of Gaillardia characterized by Prof. Gray 

 as Gaillardia acaulis n. sp. (No 120). 



Here also occurred quite abundantly a species of Lepidimn near 

 to Lepidium integrifolium Nutt., or possibly a new species (No. 16). 



